The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Vehicle powertrains typically include a prime mover, such as an internal combustion engine, a transmission and a coupling device that transfers drive torque from the prime mover to the transmission. In some instances, an engine overspeed condition can arise, where an uncontrolled speed flare occurs in the powertrain. In one example, the engine overspeed condition may arise when there is a significant upshift delay during manual shift mode of a manumatic or tap-up tap-down (TUTD) type transmission. The driver may accidentally overspeed the engine while the transmission is in the process of upshifting to the next gear.
Such overspeed conditions can result in damage to engine and transmission components. As a result, an engine overspeed protection control may be provided which reduces an engine torque request when either the engine speed or a transmission input shaft speed is exceeded. However, the engine overspeed protection may cause a drop in torque thereby adversely affecting vehicle performance. This issue can be especially troublesome in high performance vehicles, where drivers usually expect enhanced vehicle characteristics such as high power output and torque.
While current transmission control systems and methods achieve their intended purpose, there is a need for a new and improved transmission control system and method which exhibit improved upshift performance.